The normal method of discharging a liquid from a gable top carton has been to open the sealed ridge of the gable by forcing its opposite sides away from each other. This practice has generally been found objectionable because of the considerable manual effort required as well as a potential hygienic problem, due to the need for direct manipulation of the gable top from which the liquid is to be poured. It also lacks tight reclosability, such as might be needed to shake a pulp-containing juice product without splashing.
Reusable carton holding and pouring devices to engage a gable top carton have been developed in an attempt to overcome some of these problems. For example, U.S. Pat. No. 4,723,689 issued to Vallos et al. on Feb. 9, 1988 discloses one such holder having a pouring spout including a blade which cuts a circular opening in the carton wall upon rotation of the spout. However, such holders are not always available each time a consumer desires to open and dispense a liquid product from a gable top carton.
Accordingly, considerable effort has been exerted to mount an opening/reclosing feature, such as a plastic mouthpiece, in one of the sloping top walls of the gable top carton.
U.S. Pat. No. 4,214,675 issued to Schmit on Jul. 29, 1980 discloses one approach which has been taken to dispense products such as wines or other alcoholic beverages wherein it is desirable to prevent the passage of air into the container once the dispensing process has been initiated. Schmit discloses a liquid-containing pouch sealed within a carton. The pouch has a spout connected thereto which projects through a hole in the carton and which is secured to the carton by means of a flange and sleeve arrangement, said flange and said sleeve engaging one another by means of a friction fit. The spout includes a piercing means which is moved axially to rupture the pouch. Liquid to be dispensed passes from the pouch through the spout without coming in contact with the cut edge of the aperture in the paperboard carton. As the liquid is dispensed, the pouch collapses. A valve in the spout forms an airlock to restrict the passage of air into the pouch during and after dispensing of liquids therefrom. This package is both difficult to manufacture and expensive.
Another container which does not include a pouch, but which does include a pouring spout is disclosed in U.S. Pat. No. 4,483,464 issued to Nomura on Nov. 20, 1984. Nomura discloses a container body having a hole of desired size in one of the sloping panels of the gable top, the inner surface of which is coated with a thermoadhesive plastic film or an aluminum foil laminated with such a film. A pouring spout body having an inner spout with a pouring channel and an air inlet is adhered over the aperture in the carton wall to the outermost surface of the carton by means of an integral flange. A cap is placed over the upper end of the pouring spout body. The pouring spout includes a blade for tearing the film adhered over the aperture in the container body to dispense the liquid contents of the container. Once opened, the cut edges of the aperture in the carton wall are exposed to the liquid contents of the carton. In the case of a paperboard carton coated with a liquid impermeable coating on its innermost and outermost surfaces the cut edges of the aperture which are exposed by puncture of the sealing membrane tend to wick the liquid contents of the package into the paper, thereby destroying the integrity of the carton wall in the area where the spout is joined to its surface as well as creating an unpleasant physical appearance about the spout.
Still another sealed gable top carton having a mouthpiece of one piece construction is disclosed in U.S. Pat. No. 4,669,640 issued to Ando et al. on Jun. 2, 1987. Ando et al. disclose a gable top carton comprised of paperboard and having an aperture cut in one of the sloping panels of the uppermost surface of the carton. Closing the aperture is a plastic mouthpiece of one piece construction. The majority of the embodiments disclosed in Ando et al. employ a flange located opposite a multiplicity of retainer lugs along the tubular passageway in the mouthpiece. In most of the disclosed embodiments the mouthpiece is inserted from the innermost surface of the carton until the retaining lugs snap through the aperture and secure it in position for sealing. The flange located on the innermost surface of the carton wall is thereafter fused in liquid tight engagement to the edge portion of the wall around the aperture. The liquid contents of the carton pass through the tubular orifice in the one piece mouthpiece without coming in contact with the cut edges of the aperture. However, any liquid which comes in contact with the exterior of the carton, e.g., due to manufacturing wash down operations or due to condensation effects caused by temperature changes, wicks into the exposed cut edges around the aperture resulting in both poor appearance and structural degradation of the carton wall in the area of the mouth piece.
Ando et al. further disclose, in FIGS. 25 through 27, a mouthpiece embodiment which includes a flange which is sealed to the external surface of the gable top side wall around the aperture used for dispensing the liquid contents of the carton. However, this embodiment employs no innermost flange or liquid tight seal and so allows exposure of the cut edges of the aperture to the liquid contents of the carton both prior to and after opening of the carton by the consumer. Even if one were to provide an innermost moisture-barrier membrane to protect the cut edges of the aperture prior to opening of the carton by the consumer, once the moisture-barrier membrane is opened by the consumer the cut edges of the aperture would be immediately exposed to the liquid contents of the carton during the dispensing operation.
The wicking problems of the aforementioned Ando et al. carton embodiment are even further aggravated due to the manner in which the mouthpiece is opened. In particular, the mouthpiece is opened by partially separating the sealed flange from the outermost surface of the carton wall and folding it back along a hinge line in the mouthpiece. This separation of the sealed flange from the exterior surface of the carton wall substrate tends to cause portions of the moisture resistant outermost layer of the carton wall to delaminate from the paperboard during the opening process and remain secured to the mouthpiece flange after it is opened. Raw edges of the paperboard are thereby exposed in areas over which the liquid being dispensed must pass, thereby further aggravating the wicking problem in the area surrounding the aperture in the carton wall.
There have been prior art attempts to solve the aforementioned wicking problems by applying pairs of polymeric layers to opposite surfaces of a carton board wall over an aperture in the carton board wall, joining the polymeric layers coinciding with the aperture to one another through the aperture and thereafter punching a hole through the central portion of the joined layers. U.S. Pat. No. 4,397,401 issued to Ueno et al. on Aug. 9, 1983 is representative of such an approach. These techniques are usually difficult to reliably execute. Perhaps more importantly, however, they do not provide an easily reclosable pouring spout suitable for shaking the product prior to dispensing or for mess-free dispensing of liquid products such as milk, juice or liquid laundry additives from cartons comprised of paperboard laminate.
A solution to many of the aforementioned prior art problems is disclosed in the commonly assigned co-pending U.S. Patent Application of Donald E. Jones and Michael T. Brown entitled "MOISTURE IMPERVIOUS CARTON HAVING ONE PIECE POURING SPOUT SEALED TO INNERMOST AND OUTERMOST SURFACES, Ser. No. 196,418, filed on May 20, 1988. The aforementioned co-pending patent application of Jones et al. discloses a liquid containing paperboard laminate carton including a one-piece plastic spout having a pair of opposing flanges sealed about an aperture in one of the carton walls to both the innermost and outermost surfaces of the carton wall. The double flange configuration not only forms a mechanically positive interlock between the plastic spout and the carton wall, but also isolates the cut edges of the aperture in the carton wall from exposure to liquid either from within the container or from the environment through which the carton must pass from the point of manufacture until it is ready for disposal after its contents have been consumed. The spout, which is preformed so as to include one of the flanges, preferably includes a liquid passageway having a membrane type seal across its discharge orifice to provide evidence of tampering. A resealable closure member such as a screw cap or a snap-on closure is preferably held in place by means of a mating ring or groove on the spout. The cross-sectional area and configuration of the liquid passageway and discharge orifice of the spout are preferably designed to prevent complete blockage by liquid when the package contents are being dispensed during a normal dispensing cycle, i.e., when the package is not being held completely upside down.
While method and apparatus for either sequential or simultaneous sealing of both flanges of the spout of Jones et al. are disclosed in the aforementioned commonly assigned co-pending U.S. Patent Application, considerable care must be exercised to provide needed support for each flange to effect simultaneous sealing of each flange to the surface of the carton board adjacent thereto. This is due in large part to the fact that the flange sealing surfaces on opposite surfaces of the carton board do not completely coincide with one another when a spout configuration such as that disclosed in the Drawing Figures of the commonly assigned, co-pending U.S. Patent Application of Jones et al. is employed.